My MCI 7 with 8V92 and 740 auto still has a heating problem on long climbs in Arizona, or any mountains. So far I have had new thicker radiators with baffles put in, I did that what a pain, smaller fan pulley, squirlle cages taken out and cleaned, new 170 degree thermastats, new hoses, new seals around the squirrle cages, scoops at the rear of the side intakes, and also a mister system put on. I also put in a 5 gal puke tank to recover the water. I also run with the rear doors open on long climbs, which helps a lot to let the hot air out. I haven't found how the trans is cooled, don't know what I am looking for. Wondering also about a different trans cooler set up.Was thinking if there is a way to put two more radiators below the two existing radiators. I have the lower louvers on each side door and a lot of room. Was thinking of making brackets so the radiators could be swung out to get to the engine. Course would have to put in electric fans on them also.Any thoughts on if fessiable and how to plumb them and would it work?ThanksEDMCI 7

Ed - my MC7 has a third radiator mounted on the right side low with an electric fan on it that helps some on cooling (the fan really needs to be better than the one I have). I have the R & M kit on the bus and the side access panels have openings cut into them that let air in.

I can see the temprature drop a couple of degrees when I turn that fan on when climbing. I will take some pictures for you when I can and post them here.

Craig:Thanks for the info, would like to see the picks. Where are you in Oregon? My daughter lives in Portland area and I want to go see her when I sell my house and go full timming because then I will be retired.ThanksED

Have to be careful going to more "radiator". In some cases, if you increase the flow capacity too much, you can slow the speed of the coolant down to the point it may actually REDUCE cooling performance, even though you have bigger radiators.

My MCI 7 with 8V92 and 740 auto still has a heating problem on long climbs in Arizona, or any mountains.† So far I have had new thicker radiators with baffles put in, I did that what a pain, smaller fan pulley, squirlle cages taken out and cleaned, new 170 degree thermastats, new hoses, new seals around the squirrle cages, scoops at the rear of the side intakes, and also a mister system put on. I also put in a 5 gal puke tank to recover the water.† I also run with the rear doors open on long climbs, which helps a lot to let the hot air out. I haven't† found how the trans is cooled, don't know what I am looking for.† Wondering also about a different trans cooler set up.Was thinking if there is a way to put two more radiators below the two existing radiators.† I have the lower louvers on each side door and a lot of room.† Was thinking of making brackets so the radiators could be swung out to get to the engine.† Course would have to put in electric fans on them also.Any thoughts on if fessiable and how to plumb them and would it work?ThanksEDMCI 7

Hi Ed; Talked with a charter owner here in the dsesert. He suggested (as he did) that you cut the deck back under the squirrel cage approx 2". This opens up th airflow area a little and he has had no cooling problems since. You cut the deck approx 2" forward to open the hole. I have not yet done this to my MC-7, but plan to. Good Luck,

Ed, your tranny might be the culprit, since you mentioned the long climbs. I don't know if you've seen Brian Diehl's thread about how he created a lock-up solenoid switch for his Allison: http://www.busconversions.com/bbs/index.php?topic=883 Getting lockup on a climb would prevent a lot of heat on the tranny oil from hitting your engine cooling system.

Also, you can consider adding an aftermarket air cooler for the tranny oil. Hayden makes many models to choose from. My V730 uses only a large air-to-oil cooler (a massive one made by made by American Industrial Heat Transfer) and doesn't dump any of its heat into the coach cooling system.

Have to be careful going to more "radiator". In some cases, if you increase the flow capacity too much, you can slow the speed of the coolant down to the point it may actually REDUCE cooling performance, even though you have bigger radiators.

The coolant flow through the motor should be the same regardless of your radiator size; Nevertheless, I think I know what you were trying to say, but when it comes to radiator cooling, I can not think that there would be a situation where you can have too much. When the coolant slows down in a big radiator it just has more time to cool. Which is a good thing right?

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L. Christley - W3EYE Amateur ExtraBlue Ridge Mountains, S.W. VirginiaItís the education gained, and the ability to apply, and share, what we learn.Have fun, be great, that way you have Great Fun!

Agreed, more radiator is better, especially in marginal situations. MCI never designed a cooling system exactly according to DD specifications. They only designed for about 1/2 the parameter (one aspect) called for in DD specs. They also selected a lower max ambient temp than DD specified. However,

Too much of a "good thing" will get you back in trouble!!!

If you slow down the coolant too much, i.e., lots more radiator with same coolant pump capacity, you lose the turbulence effect that fast running coolant in the tube causes. It keeps the coolant "mixing" so hot coolant is continuously exposed to the radiator tube and it gives up its heat to the air.

The technical term when it slows is the coolant "stratifies" meaning is layers, with the cool fluid forming a tunnel for the hot coolant running through and not giving off as much heat as it could.

You canít beat an education, this is the neat thing about this board, one can learn a thing or two. Iím going to drop this on some fleet mechanics at work and see what experiences they have had with it. I intentionally didnít take thermodynamics in collage so I was not exposed to that concept. With the different densities involved, I could see where this could be possible.

Thanks

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L. Christley - W3EYE Amateur ExtraBlue Ridge Mountains, S.W. VirginiaItís the education gained, and the ability to apply, and share, what we learn.Have fun, be great, that way you have Great Fun!

Ed - here are three shots of the third radiator. It lives below the right side radiator back of the side engine hatch. The engine hatches have R & M updates with vent holes. Their is a chunck of mudflap that ducts air to the radiator. There is a picture of the door open and also one of it shut so you can see how it works. The other shot is through the back door and you can see the radiator with shroud and the back of the wheel well on the right side.

It does take a couple of degrees off on a climb (more on a shallow climb) but I think it could be better with better ducting and a better fan. I also think venting the rear engine doors near the blower outlets in the engine bay would make sense... the heat would leave the engine bay much sooner.

You already have a third radiator if you have not removed you bus heat. I use my large bus heat radiator for extra cooling. In the summer I can turn the heater on and I made it so I can exzaust the bus heat to the out side. In the winter I return the heat to the inside.

Craig,† † That looks like the transmission cooler I installed in our MC-8 (same location). We re-routed the transmission cooler hoses so the transmission fluid goes to the this cooler first, through the OEM cooler, and then returns to the transmission. Since doing this, all temperatures (water, oil, and transmission fluid) run about 10-15 degrees cooler. And that is without turning on the fan. We have not been in any mountains yet see give it a real test.† † Do you pull outside air in, or push inside air out with the fan?† Jack